I've managed to set up my workers and they used to execute without issue (in development) but now they don't in either production or development (I'm guessing after changing from SQlite3 to PostgreSQL).

When I run a rake command to run the workers with rake resque:work QUEUE=* I get the following error and stack trace:

getaddrinfo: nodename nor servname provided, or not known

I get the following errors when running heroku rake resque:work QUEUE=* in the console to test pending workers in the queue.

It looks like your app can not connect to Redis server. Did you provide valid connection details for production environment? Is you Redis server available? Isn't it behind firewall are some private network?